May 19, 1994
12:00 AM (EDT)

News Release Number: STScI-1994-20

Hubble Observes the Supernova in the Whirlpool Galaxy

The full news release story:

NASA's Hubble Space Telescope has returned valuable new images of
supernova 1994I in the inner regions of the "Whirlpool Galaxy,"
M51, located 20 million light-years away in the constellation
Canes Venatici. The images were taken with the Wide Field and
Planetary Camera 2 (WFPC2).

The supernova was discovered by amateur astronomers on April 2,
1994 and has been the target of investigations by astronomers
using ground-based optical and radio telescopes. At its
brightest, around April 10, the supernova was about 100 million
times brighter than the Sun.

Previous observations show that SN 1994I is a very unusual
supernova, called "Type Ic," for which very few examples have
been studied carefully.

Following initial observations with the International Ultraviolet
Explorer satellite, which demonstrated that the supernova could
be detected in the ultraviolet, a preplanned series of
observations was initiated by the international SINS (Supernova
Intensive Survey) team, headed by Dr. Robert P. Kirshner of
Harvard-Smithsonian Center for Astrophysics.

The SINS group is using HST to study supernovae in the
ultraviolet shortly after they are discovered, and at optical
wavelengths as they become too faint to monitor from the ground.
They hope to learn which stars explode as supernovae, what
chemical elements are ejected by the eruption, and how to use
these bright events as yardsticks for measuring the size of the
universe.

For example, the Supernova 1987A, located in the nearby Large
Magellanic Cloud, has been studied by the SINS team since the
launch of the HST in 1990 and will continue to be a target of
investigations.

A supernova is a violent stellar explosion that destroys a star,
while ejecting the products of nuclear burning into the gas
between stars.

Hubble Space Telescope has the unique capability of being able to
image and to measure the spectra of distant supernovae in
ultraviolet light. As the M51 supernova ages, Hubble will see
more deeply into the interior of the exploded star. This will
allow astronomers to probe the chemical composition of the debris
and to learn more about the type of star that exploded.
Debris from supernova explosions play a central role in
increasing the heavy element abundance of galaxies. The material
that makes up the Sun, the Earth, and our bodies was once inside
stars that exploded long before the solar system formed about
five billion years ago.